Research On Technologies Of Narrowband Anti-jamming And Suppresion In Spread Spectrum TT&C Satellite Transponder

The technique of spreading spectrum has got rapid progess in satelline systembecause of its inherent anti-jamming character. However, processing gain is alwaysfinite. That it could break off the system TT&C link when the NBI power exceeds thesystem’s inherent anti-jamming threshold. Further more, with the high speeddevelopment of spaceflight carrer, the space invironment become more and morecomplex, the security of satelline TT&C attached importance attention. Thereforeresearching more efficient techniques to suppress the narrowband interference has greadpractical significance. Main research results are showed as follow.1.The characteristic satelline spread spectrum TT&C system signal and someclassical anti-jam suppression arithmetic are analyzed. This arithmetic consist of linearand non-linear anti-jam suppression arithmetic in time domaim, spectrum domainanti-jam suppression arithmetic which used widely in engineering and code assistanttechnologies, and compared the advantage and disadvantage about those arithmetics.Studyied mathematic modules and signal character about the three narrowbandinterference.2.Designed and completed an arithematic in satellite TT&C transponder systemanti-jam suppression based on FPGA, combine with time domain and frequency domainadvantage and the pretical requirement in satellite TT&C system. A gread deal of workshad done in emulate the arithmetic anti-jam suppression performance for the differentspectrum and different power of NBI by compare the two parameters about InterferenceSignal Ratio improment(ISR imp) and Capture peak improment (Capi mp) with thearithmetic or not.3.Take important attention in test the arithmetic at different condition such as indifferent frequency and different range. With the help of parameter andthat it is very easy to verify the performance of arithmetic. In the best ideal condition,we can improve capture peak35dB and depress30dB ISR.4.Make full use of satellite TT&C system test equipment to test the anti-jamsuppression arithmetic and received some test date. By analyse the data and experimentwe can made an result, the experiment result accord with the emulate result that thearithmetic could improve the ability of anti-jam20dB based on the system’s originalability.